docs: def determine_sex(
      snps, y_snps_not_null_threshold=0.1, heterozygous_x_snps_threshold=0.01
  ):
      """ Determine sex from SNPs using thresholds.
  
      Parameters
      ----------
      snps : pandas.DataFrame
      y_snps_not_null_threshold : float
          percentage Y SNPs that are not null; above this threshold, Male is determined
      heterozygous_x_snps_threshold : float
          percentage heterozygous X SNPs; above this threshold, Female is determined
  
      Returns
      -------
      str
          'Male' or 'Female' if detected, else empty str
      """
  
      if isinstance(snps, pd.DataFrame):
          y_snps = len(snps.loc[(snps["chrom"] == "Y")])
  
          if y_snps > 0:
              y_snps_not_null = len(
                  snps.loc[(snps["chrom"] == "Y") & (snps["genotype"].notnull())]
              )
  
              if y_snps_not_null / y_snps > y_snps_not_null_threshold:
                  return "Male"
              else:
                  return "Female"
  
          x_snps = len(snps.loc[snps["chrom"] == "X"])
  
          if x_snps == 0:
              return ""
  
          heterozygous_x_snps = len(
              snps.loc[
                  (snps["chrom"] == "X")
                  & (snps["genotype"].notnull())
                  & (snps["genotype"].str[0] != snps["genotype"].str[1])
              ]
          )
  
          if heterozygous_x_snps / x_snps > heterozygous_x_snps_threshold:
              return "Female"
          else:
              return "Male"
      else:
          return ""